<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script type="text/javascript">
        //javascript不允许重载
        var fun=function (){
            alert("无参函数");
        }
        var fun2=function (a,b){
           alert("有参函数a="+a+"，b="+b);
        }
        var fun3=function (a,b){
            return a+b;
        }
        alert(fun2(100,10));
    </script>
</head>
<body>

</body>
</html>